Highfields Amateur Radio Club Operators Pages.

Morse Code.By Brian MW0GKX(with error corrections by Bill, VK6QW).

The Morse Code.

Morse code is an on-off code. It is not a true binary code since the gaps between the dots and dashes and between the letters themselves are also significant. However, it is admirably suited to a simple transmitter, the emission or continuous wave (CW) from which only has to be turned on or off in order to transmit the code. That is why CW transmitters are easy to build. Additional features of CW include a very narrow bandwidth, so that a lot of signals can exist side-by-side in a given frequency band, useful at short-wave frequencies which are crowded; and the fact that CW telegraphy can be "copied" through very heavy interference and at very low signal levels. The penalty for the low bandwidth is the fairly slow rate at which information can be sent.

Hand sent CW telegraphy is now mostly an amusement for those of us who like "pounding brass", and is no longer used commercially. High speed error-correcting codes, sent via UHF links to satellites where the large bandwidth is not a problem since there is plenty of spectrum space at UHF, have long superseded the brasspounder's art. Statements at the beginning of 1999 that Morse code is "no longer used" were not true. Oddly, there is one high-tech industry where Morse code is still used: airline pilots have to know it. Admittedly it is only at about 5 wpm, and only three letters at a time. Beacons which radiate in the medium wave region of the spectrum use three-letter identifiers sent very, very slowly in Morse.

Morse code is no longer a requirement for access to the HF bands in the UK, as it used to be, and it is being dropped as a requirement for HF operation in other countries as well. This follows the WRC (World Radiocommunication Conference) 2003 decision to delete the requirement to prove Morse Code ability from the International Radio Regulations, leaving individual administrations to decide if they want it retained or not.

Different versions of Morse code.

Morses' original code was not quite the same as the one in use today. In particular C, O, R, Y and Z contained spaces within the letter codes which must have been tricky to handle, and the numbers were different. This "American" Morse code was in wide use until the 1920's. For international use it was modified as a result of a conference in Berlin in 1851, this regularised the code on a more rational basis and eliminated the spaces within the letters, but equally important from a European point of view it provided codes for accented letters.

Both the original code and the current International Code use the same principle, that the commonest letters have the shortest codes. How to find out what the letter incidence is? To find this out Morse had a marvellous idea. He went to his local newspaper. There he found the page compositors making up pages by hand from individual letters, capital letters were in one case or tray of type, and this was set above the case of small letters. This is the origin of 'upper and lower case' letters. Morse simply counted the number of pieces of type for each letter, thinking, soundly enough, that this must be related to the number needed. Thus "e" has the shortest code, "dit", whereas "z"
is (now) "da-da-di-dit" and "q" (now) "da-da-di-dah". Notice that I write them as they sound; Morse Code was a visual code in the early days, but it is now an aural one. An interesting point to note is that the symbol for "V", "di-di-di-dah", is also the opening phrase of Beethoven's Fifth (V) Symphony. Morse was 20 years younger than Beethoven, was he a fan of the composer?

Morse Code can, of course, be decoded by computer but that's not much fun. Some of the earliest telegraphs used with land-lines employed an inked stylus which was moved sideways when a signal was received and which wrote on a moving paper tape.

The International Morse Code.

International Morse code is composed of five elements:

Short mark, dot or "dit" (.) = one unit long.

Longer mark, dash or "dah" ( — ) = three units long.

Intra-character gap (between the dots and dashes within a character) = one unit long.

Short gap (between letters) = three units long.

Medium gap (between words) = seven units long.

A popular method for learning Morse Code is the Farnsworth method. Farnsworth Method Morse is composed of characters sent at the correct spacing with longer than standard spacing between them. This means that the mind gets used to hearing the "right sounds" while having plenty of time to think about them. All the great code schools of the past used the Farnsworth method of teaching and you can sometimes hear it around the bands as operators who are not fully proficient are using it for a chat.

Letters.

A . —

B — . . .

C — . — .

D — . .

E .

F . . — .

G — — .

H . . . .

I . .

J . — — —

K — . —

L . — . .

M — —

N — .

O — — —

P . — — .

Q — — . —

R . — .

S . . .

T —

U . . —

V . . . —

W . — —

X — . . —

Y . — . —

Z — — . .

Numbers.

1 . — — — —

2 . . — — —

3 . . . — —

4 . . . . —

5 . . . . .

6 — . . . .

7 — — . . .

8 — — — . .

9 — — — — .

0 — — — — —

Other (punctuation etc).

Full Stop[.]. — . — . —

Colon[:]— — — . . .

Comma[,] — — . . — —

Semicolon[;] —.—.—.

Question[?]. . — — . .

Apostrophe[']. — — — — .

Quotation Mark["]. — . . — .

Bracket Open[(]— . — — .

Bracket Close[)]— . — — . —

At Sign[@]. — — . — .

Plus[+]. — . — .

Minus or Hyphen [-]— . . . . —

Slash[/]— . . — .

Equal Sign[=]— . . . —

Prosigns (procedural signals).

Wait. — . . .

Error. . . . . . . .

Understood. . . — .

End of work. . . — . —

Starting Signal— . — . —

Invitation to transmit (over)— . —

Non English Extensions.

ä / æ /ą. — . —

à / å. — — . —

ç / ĉ /ć— . — . .

ch / š / ĥ— — — —

è / ł. — . . —

é / đ / ę. . — . .

ĝ— — . — .

ĵ. — — — .

ñ / ń— — . — —

ö / ø / ó— — — .

ś. . . — . . .

þ. — — . .

ü / ŭ. . — —

ź— — . . — .

ż— — . . —

NOTES:

There is no standard representation for the exclamation mark (!), although the KW digraph ( — . — . — — ) was proposed in the 1980s by the Heathkit Company. While Morse Code translation software prefers this version, on-air use is not yet universal as some amateur radio operators in Canada and the USA continue to prefer the older MN digraph ( — — — . ) carried over from American landline telegraphy code.

The "&", "$" and the "—" sign are not defined inside the ITU recommendation on morse code. The "$" sign code was defined inside the Phillips Code (huge collection of abbreviations used on land line telegraphy) as ( . . . — . . — ). The representation for the "&" sign is the morse pro sign used for "wait" ( . — . . . ). The underscore "_" is ( . . — — . — ).

Learning Morse Code.

There are as many ways to learn morse code as there are stars in the sky! There is no "right" way to do it. One thing I have found useful is the the dichotomic search table, or Morse Code Tree, shown below. To use it you branch left at every dit and right at every dah until the character is finished. Click on the image for a larger, printable, version (print it in landscape).

There is also a PDF of the 1940s - 50s book The New Morse Code Manual (fifth edition), issued to the Air Training Corps, that you may find useful (1.85 Mb).

Abbreviations.

As well as learning the code, one has to learn the abbreviations as well or hours could be wasted tapping out every letter of every word, this could lead to loss of intrest on the receiving end and also sending errors. Abbreviations differ from prosigns for Morse Code in that they observe normal interletter spacing; that is, they are not "run together" the way prosigns are. Also the "Q" Codes are used as well.